Description
Core area=max(0,width-2*depth)*max(0,length-2*depth); edge area is total rectangle minus core.
Habitat geometry describes lengths, overlaps and areas on explicit ideal shapes. An edge-to-area ratio and a root-depth overlap summarize different spatial relations; neither identifies a species-specific edge effect or functional connectivity. Supplied nonoverlap flags do not replace a geometric check.
Core area=max(0,width-2*depth)*max(0,length-2*depth); edge area is total rectangle minus core.
When to use this tool
Use Field Edge Habitat Core Area Term when checking the stated ideal habitat, buffer or interval geometry.
How to use the tool and how it works
- Enter width, length, edgeDepth. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read coreArea, edgeArea. Use the output convention below.
Require nonnegative rectangular width, length and edge depth. Core area=max(0,width-2*depth)*max(0,length-2*depth); edge area is total rectangle minus core.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| width | Width | Required. Finite number; minimum 0. |
| length | Length | Required. Finite number; minimum 0. |
| edgeDepth | Edge Depth | Required. Finite number; minimum 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| coreArea | Core Area | Required. Finite number. |
| edgeArea | Edge Area | Required. Finite number. |
{
"input": {
"width": 100,
"length": 200,
"edgeDepth": 10
},
"output": {
"coreArea": 14400,
"edgeArea": 5600
}
}Limitations and assumptions
- Uniform inward edge depth is a supplied geometric assumption, not an ecological effect-distance estimate.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use mapped boundaries and appropriate complete spatial/ecological models for real habitat function or field layout.
References
Similar or alternative tools
- Habitat Buffer Edge Area Factor
Return nominal rectangle area=length*width and add the signed cornerCorrection for correctedArea.
- Habitat Edge Strip Area Ratio
Sum length*width, require the sum<=plotArea and return its area share.